Physical textile properties of webs are controlled via the chemical and physical textile properties of the fibers and filaments which form them. The fiber or filament raw materials are selected based on the desired chemical and physical properties, with regard to their ability to be dyed, their chemical resistance, their thermal ductility, or their absorption capability. The module and stress-strain properties of the fibers or filaments are dependent on the material properties which may be controlled via the selection of the degree of crystallization and/or the degree of orientation and the profile geometry in order to influence the bending rigidity, the power, or the specific surfaces of the individual fibers or filaments. The sum of the physical textile properties of the fibers or filaments forming a fabric is ultimately controlled via the mass per unit area. Examples of oppositional demands on fabrics are geotextiles made of highly rigid, highly drawn, large-titrant, and three-dimensionally woven filaments, e.g., chewing tobacco pouches made of cellulosic wet nonwoven fleece, or nylon hose made of a fine, texturized polyamide fabric.
Nonwovens made of very fine continuous filaments, which are manufactured using bi-component continuous filaments, are known from EP 0 814 188 B1 in which the two components viewed in cross section are situated in an orange wedge formation in an alternating manner in the starting filament and, after lapping to form a fabric, are split up into microfiber filaments via liquid pressure jets and are simultaneously bonded by entangling the filament strands. The obtained multicomponent spunbonded nonwoven is determined by the physical textile properties of its two types of elementary filaments, the titers of both elementary filaments diverging only slightly from one another.
An additional way to combine oppositional properties in one fabric is to manufacture composites made up of two or more fabrics. The individual properties are combined by joining the individual fabrics via known joining methods such as sewing, gluing, laminating. For this purpose, the individual fabrics have to be manufactured separately and are subsequently joined together. U.S. Pat. No. 5,679,042 describes a method for manufacturing a nonwoven having a fiber structure, which has a pore size gradient, the fibers, made of at least one polymer resin, being produced and lapped to form a nonwoven having an average pore size and a selective treatment, using a heat source, being subsequently performed, thereby resulting in shrinkage of the fibers and reduction of the average pore size.